Kim Kardashian and Kanye are expanding their family again.

A source close to the couple told CNN Wednesday that they are expecting their fourth child via surrogate this year.

The couple welcomed their daughter Chicago West via surrogate last January. The couple also have daughter North, 5, and 3-year-old son Saint. Us Magazine was the first to report the news.

Kardashian did not confirm that the baby was on the way until well into the pregnancy. She also opted to reveal the news on her E! reality show, "Keeping Up With the Kardashians."

She has been open over the years about her struggles to get pregnant and documented the process on the show. While pregnant with North, Kardashian West suffered from pre-eclampsia, a complication characterized by high blood pressure. She also had placenta accreta in both pregnancies, which occurs when the placenta attaches too deeply in the uterine wall.

Following the birth of North, she wrote about the terrifying moment her doctor realized the placenta had attached too deep.

Kim said she was prepared to have her uterus removed following the birth of Saint.